Hey ... your definition sounds good!
I think to understand the notion of belonging = acceptance, you must understand exclusion.
In my opinion belonging brings about acceptance in that we cannot help but belong. E.g. one that likes pop music, belongs (and is therefore accepted) into a group of people with a similar like. Those that don't may be accepted (and therefore belong) to people that like alternative music instead. Regardless of their specific likes, both persons are observed to belong to a group of people who like music....
Argh, the analogy continues lol
Basically, there are so many levels of acceptance, but while belonging exists, acceptance remains inevitable...
Isn't to belong, to be accepted?